The present invention relates to belt connectors of the type having wire hooks to interconnect the opposite ends of a belt. Each wire hook has two shanks arranged on opposite sides of the belt, and furthermore has hook ends adjoining the shanks, wherein the hook ends are pressed into the carcass of the belt. Each wire hook also has a coupling loop connecting the two shanks. The belt connector furthermore has a flat cover element that extends on both sides of the belt to cover portions of the hook assembly. The cover element extends across the width of the belt, and has a carrier material and a coating applied to the side facing the belt, that is made of a thermoplastic or an adhesive, especially a hot melt adhesive or an elastic adhesive, for attaching the cover element to the belt.
The invention furthermore relates to a method for producing such a belt connection.
A connection of the type cited in the foregoing is known from WO 2007 025567 A1. The wire hooks are held in a strip-like carrier material made of a textile fabric. One side of the carrier material is coated with an adhesive or provided with a thermoplastic. When the connection is made, heat generated by press jaws causes the carrier material and belt to fuse together. The cover element covers portions of the wire hooks and the belt end in order to prevent the wire hooks, especially damaged wire hooks, from damaging or otherwise having a negative effect on goods being conveyed on the belt.
Belt connectors embodied as wire hooks and connected to one end of a belt using a cover element that extends across the width of the belt are furthermore known from EP 1 338 825 A1. The belt is for instance embodied as a plastic belt, especially a polyurethane belt. The cover element is embodied as a fabric belt or plastic molded part and is provided with a layer of adhesive, especially a layer of hot glue, or an elastic adhesive. The wire hooks are attached to the belt and the cover element is added preferably in one operation, wherein the cover element is glued to the shanks of the hooks and the belt, especially using heat.
A method for pressing wire hooks into flat fabric comprising plastic is known from DE 36 42 803 A1. The shanks of the wire hooks are heated prior to bending. During bending the plastic of the flat fabric is partially plasticized and the wire hooks are pressed together, such that in their final pressed state, the exterior dimension of the shanks is never greater than the thickness of the flat fabric.
DE-PS 732 524 describes belt connectors that are embodied as wire hooks and connected to one end of a belt. The shanks of the wire hooks are embedded in a rubber cover layer of the belt. The belt comprises a fabric core and the rubber coatings. Producing such a connection is very complex because vulcanization is required in order to apply the rubber cover layers.
When joining belts, such as screen conveyor belts, press conveyor belts, filter conveyor belts, transport conveyor belts, and flat conveyor belts, it is known from DE 100 29 571 A1 to spray the end of the belt in a tool with a free-flowing material that consolidates when cooled. The material creates a permanent connection to the belt in the longitudinal direction of the belt at the given tensile forces. Each half of the belt joint is provided with alternating projections and recesses. The projections are provided with aligned channels through which a cotter pin can be passed. Substances used for the free-flowing materials are metals and plastics, such as thermoplastics, thermosetting plastics, and condensation resins, especially polyurethanes. Woven, knitted, laid, homogenous, and coated belts made of textiles, metal substances, plastics, and metal fabrics are also used commercially. Joining such belts in the manners described above is very complex, and in particular, is very time-consuming.
Devices such as that in accordance with EP 0 682 645 B1 are used for dewatering suspensions. These devices have belts that are made of a porous filtering web. The spaces in the filtering web can be used to dewater the suspension. Such a suspension is used for instance with sludge. Two conveyor belts are arranged relatively close to one another. They press the suspension between them during conveying so that the spaces in the belts are dewatered.
Such devices are also used for instance for extracting fruit and vegetable juices, dewatering draff, and producing algae and herbal extracts. The fluid is drained off by pressing the products between conveyor belts that are made of a filtering web.
With such devices, it is necessary to remove the filter cake after the dewatering has taken place. The filter cake is removed using wipers that contact the rotating belt. Thus, the wipers also contact those areas of the belt in which belt connectors and their covers are located. These areas are then subjected to increased wear, especially when material that has abrasive parts is being conveyed, for instance sand particles.